The speedy success of Germany invading France in 1940 had more to do with their use of radios and giving commanders on the field some latitude on how to accomplish objectives than with the consequences of the Versailles treaty on the population. The French Army and the British Expeditionary Force were more stuck in a WWI style of command from the top that proved vulnerable to speed. But it wasn't clear cut as the "fast attack" plan was initially rejected by the German top brass, themselves still stuck in the past.